No the 24 was a perfect focal length for my landscapes. I seldom use the 17 end of my 17-40 either unless I am trying to exaggerate perpective, but then it is hard to achieve adequate focus through-out. The tilt does this MUCH better, meaning you can exaggerate perspective more by getting closer to the foreground without losing focal depth.
Shift is awesome for stitching panoramic landscapes, which mostly makes up for the smaller angle of view. When I say "stitch" the 2 shifted shots are simply dropped together in PS with a blurred edge and look perfect - no fancy software required. Huge time saver there. Less funky polariser effects too because the camera is not rotated with respect to the sun.
The only reason that I don't own the Mk2 already is that a house purchase has intervened
Just buy the Mk 2 and if it doesn't work out, send it my way...